Charles ruled in an era of great religious turmoil in Britain and at the end of the English Civil War he was executed. At his trial, he was charged with attempting to govern as an absolute monarch rather than in combination with Parliament; with fighting against his people; with continuing the war after the defeat of his forces (the continuation is often regarded as the Second English Civil War); with conspiring after defeat to promote yet another continuation; and with encouraging his troops to kill prisoners of war. (Robertson ibid ch 10)

Charles is regarded by many members of the Church of England as a martyr because, it is said,[1] he was offered his life if he would abandon the historic episcopacy in the Church of England. It is said he refused, however, believing that the Church of England was truly "Catholic" and should maintain the Catholic episcopate. His designation in the Church of England's calendar is "Charles, King and Martyr, 1649".[2]Mandell Creighton, Bishop of London, wrote "Had Charles been willing to abandon the Church and give up episcopacy, he might have saved his throne and his life. But on this point Charles stood firm: for this he died, and by dying saved it for the future." In fact, Charles had already made an Engagement with the Scots to introduce Presbyterianism in England for three years in return for the aid of Scots forces in the Second English Civil War.[3]

When Charles was beheaded on 30 January 1649, Philip Henry records that a moan was heard from the assembled crowd, some of whom then dipped their handkerchiefs in his blood, thus starting the cult of the Martyr King. However, no other eyewitness source, including Samuel Pepys, records this. Note also that Henry's account was written during the Restoration (i e some 12 years after the event), Henry was 19 when the King was executed, and he and his family were Royalist propaganda writers. (See J Rushworth in R Lockyer (ed) The Trial of King Charles I pp. 133–4)

There is some historical debate over the identity of the man who beheaded the King, who was masked at the scene. It is known the regicides approached Richard Brandon, the common Hangman of London, but that he refused, and contemporary sources do not generally identify him as the King's headsman. Ellis's Historical Inquiries, however, name him as the executioner, stating that he stated so before dying. It is possible he relented and agreed to do the deed, but there are others who have been identified. William Hewlett was tried for the murder after the Restoration and convicted. In 1661, two people identified as "Dayborne and Bickerstaffe" were arrested but then discharged. Henry Walker, a revolutionary journalist, or his brother William, were suspected but never charged. Various local legends around England name local figures.

It was common practice for the head of a traitor to be held up and exhibited to the crowd with the words "Behold the head of a traitor!" Although Charles' head was exhibited, the words were not used. In an unprecedented gesture, one of the prominent leaders of the revolutionaries, Oliver Cromwell, allowed the King's head to be sewn back on his body so the family could pay its respects. Charles was buried privately and at night on 7 February 1649, in the Henry VIII vault inside St George's Chapel in Windsor Castle. The King's son, King Charles II, later planned an elaborate royal mausoleum, but this never eventuated.

The Calendar of the Book of Common Prayer included among the Red Letter Days commemorations of the Gunpowder Plot, the birth and restoration of King Charles II, and the execution of King Charles I. In addition, a proclamation made at the beginning of each reign from that of King Charles II to that of Queen Victoria, annexed special services for these days to the Prayer Book by royal mandate (approved unanimously by Convocation). In the time of Queen Victoria, in 1859 the State Services were omitted from the Prayer Book by royal and parliamentary authority but without the consent of Convocation. The printers of the Prayer Book, without any authority at all, thereupon omitted these Red Letter Days from the Prayer Book. Of the three commemorations, only that of King Charles I has been restored in the calendar in the Alternative Service Book of 1980 - although not as a Red Letter Day - and a new collect composed for Common Worship in 2000. The commemoration has yet to be restored to the Book of Common Prayer but it is included in some of the calendars of other Churches of the Anglican Communion. (There is a full discussion of these matters in Vernon Staley, Liturgical Studies.)

Founded in 1894, the Society's stated purpose was "intercessory prayer for the defence of the Church of England against the attacks of her enemies." Since then, the objectives have extended to religious devotion in keeping with the traditions of Anglo-Catholicism.

Promotion of a wider and better observance of the Feastday of St Charles, 30 January.

Work for the reinstatement of the Feast of St Charles in the calendar of The Prayer Book from which it was removed in 1859 without the due consent of the Church as expressed in Convocation; the Feast was restored to the calendar in the Alternative Service Book of 1980 and a new collect composed for Common Worship in 2000.[4]

The propagation of the true knowledge about the life and times of S. Charles, and winning general recognition of the great debt the Church of England owes to him for his faithfulness unto death in defence of the Church and Her apostolic ministry.

The support of efforts to build and equip churches dedicated under the patronage of S. Charles the Martyr (both at home and overseas).

Outside of England, the objectives vary slightly, especially in regard to the Feast of St Charles, which is widely observed by the church in some places and not in others.

In the United States and Canada, the Society is independently constituted as the American Region. The Society's activities in the United States can be traced back to 1895, within a year of the Society's foundation in 1894 in London.[5] The American Region is incorporated under the General Laws of the State of Maryland as a not-for-profit corporation, the "Society of King Charles the Martyr, Inc.", and is tax-exempt under Section 501(c)(3) of the IRS code, both effective as of 8 April 2008. The American Region is governed by a Board of Trustees, and holds a Solemn Mass of the Feast of St Charles Martyr on a Saturday close to January 30. In addition, the American Region confers an honor on some members through membership in the Order of Blessed William Laud.

Each of these societies champions one aspect of Catholic faith and practice that otherwise could be considered underemphasized by the Anglican Churches as a whole. For the Society of King Charles the Martyr, this is the cultus of Charles I of England, King and Martyr.

^Episcopal Church. Diocese of Eau Claire. "annual convention". Journal of the Diocese of Eau Claire (The Diocese). Whereas, as Bishop Creighton in 1895 said, "Had Charles been willing to abandon the Church and give up the episcopacy, he might have saved his throne and his life, but on this point he stood firm. For this dying, saved it for the future